Windows Server powers many of the worlds' largest datacentres,
enables small businesses around the world, and delivers value to
organisations of all sizes in between. Building on this legacy,
Windows Server 2012 redefines the category, delivering hundreds of
new features and enhancements spanning virtualization, networking,
storage, user experience, cloud computing, automation, and more.

Simply put, Windows Server 2012 helps you transform your IT
operations to reduce costs and deliver a whole new level of
business value.

Both Standard and Datacentre editions provide the same set of
features; the only thing that differentiates the editions is the
number of Virtual Machines (VMs).

A Standard edition license will entitle you to run up to two VMs on
up to two processors (subject to the VM use rights outlined in the
Product Use Rights document). A Datacentre edition license will
entitle you to run an unlimited number of VMs on up to two
processors. All features that are available in the Datacentre
edition are also available in the Standard edition, including high
availability features like failover clustering. The only difference
between the two editions will be virtualization rights.